---
title: LowLevelInstanceTransformResource
framework: realitykit
role: symbol
role_heading: Class
path: realitykit/lowlevelinstancetransformresource
---

# LowLevelInstanceTransformResource

A GPU-managed buffer that stores an array of per-instance transforms for GPU instancing.

## Declaration

```swift
final class LowLevelInstanceTransformResource
```

## Overview

Overview Assign a LowLevelInstanceTransformResource to a LowLevelMeshInstance via setInstanceTransforms(_:) to issue a single instanced draw call that renders multiple copies of the mesh. Each entry in the buffer is a float4x4 model-to-local transform. The renderer computes the final world transform for each instance as meshInstance.transform * instanceTransforms[i]. Create a LowLevelInstanceTransformResource using makeInstanceTransformResource(instanceCapacity:).

## Topics

### Inspecting instance counts

- [instanceCount](realitykit/lowlevelinstancetransformresource/instancecount.md)
- [instanceCapacity](realitykit/lowlevelinstancetransformresource/instancecapacity.md)

### Reading transform data

- [read(_:)](realitykit/lowlevelinstancetransformresource/read(_:).md)
- [read(commandBuffer:)](realitykit/lowlevelinstancetransformresource/read(commandbuffer:).md)

### Replacing transform data

- [replace(_:)](realitykit/lowlevelinstancetransformresource/replace(_:).md)
- [replace(commandBuffer:)](realitykit/lowlevelinstancetransformresource/replace(commandbuffer:).md)

### Instance Methods

- [update(_:)](realitykit/lowlevelinstancetransformresource/update(_:).md)

## See Also

### GPU resources

- [LowLevelMeshResource](realitykit/lowlevelmeshresource.md)
- [LowLevelMeshPart](realitykit/lowlevelmeshpart.md)
- [LowLevelMeshInstance](realitykit/lowlevelmeshinstance.md)
- [LowLevelMeshInstanceArray](realitykit/lowlevelmeshinstancearray.md)
- [LowLevelBufferResource](realitykit/lowlevelbufferresource.md)
- [LowLevelBufferSlice](realitykit/lowlevelbufferslice.md)
- [LowLevelTextureResource](realitykit/lowleveltextureresource.md)
- [LowLevelMaterialResource](realitykit/lowlevelmaterialresource.md)
- [LowLevelDeviceResource](realitykit/lowleveldeviceresource.md)
- [BoundingSphereBox](realitykit/boundingspherebox.md)